In the case include no stdlib.h file, the function getenv() return a minus value.

#include <stdio.h>

#include <stdlib.h>

void main(){

	int rc;

	char *env = NULL;

	

	env = getenv("LIB");

	printf("&env = %d \n", env);

	if(env){

		printf("config home:%d\n", env);

	}

	

	env = getenv("HOME");

	printf("&env = %d \n", env);

	if(env){

		printf("home:%s\n", env);

	}

	

}